Early-onset well differentiated pancreatic neuroendocrine tumors: Clinical presentation, pathologic features, and oncological outcomes.

Abstract

507 Background: Young onset of several gastrointestinal cancers is associated with more advanced disease and poor oncological outcomes, however, this association has not been fully investigated for well differentiated pancreatic neuroendocrine tumors (PanNET). Our study aimed to evaluate clinical and pathological differences as well as disease outcomes between young-onset PanNET (YO-PanNET) and late-onset PanNET (LO-PanNET). Methods: Patients with localized PanNET who underwent surgery at Memorial Sloan Kettering Cancer Center between 2000 to 2017 were identified. Those with hereditary syndromes, metastatic disease, and postoperative mortality were excluded. YO-PanNET was defined as <50 and LO-PanNET >50 years of age at time of diagnosis. Family history, clinical and pathology characteristics, were recorded. Fisher’s exact test was used to detect difference between the age groups. Kaplan-Meier method was used to investigate age prognostic significance. Results: A total of 366 patients were identified, 84 (23%) with YO-PanNET. Compared with LO-PanNET, YO-PanNET were less likely to have a personal history of another cancer (p<0.001) and a first-line relative with cancer (p<0.015). We did not observe any significant differences between YO-PanNET and LO-PanNET with regards to pathology features such as tumor grade (p=0.7), size (p=0.5), nodal metastases (p=0.8), and stage of disease (p=0.7). With a median follow-up of 68 months (range 0-238), 5-year recurrence-free survival was 76% and 83%, and 10-year RFS was 69% and 78%, respectively, in YO-PanNET and LO-PanNET (p=0.12; see Table) with similar 5- and 10-year overall survival (p=0.31). Conclusions: In this large retrospective surgical series, we found that YO-PanNET is not associated with an increased rate of personal or familial history of cancer. Pathological characteristics and long-term oncological outcomes do not significantly differ between YO-PanNET and LO-PanNET. Current efforts include next-generation sequencing analysis in the resected surgical specimens to evaluate for genomic biomarkers of recurrence.[Table: see text]